As a conventional gear pump, for example, an art described in Patent Publication 1 has been shown. The gear pump described in this publication houses a pump assembly constructed from a driving shaft that supports a driving gear, a driven shaft that supports a driven gear, a pair of side plates, and a seal block, in a body case. On an abutting surface between this side plate and the seal block, a soft seal member is placed, and thereby ensures seal integrity.    Patent Publication 1: Japanese Patent Application Kokai Publication No. 2001-214870